The need is known in the field of portable weapons, and in particular of grenade launchers, to be able to determine the instantaneous attitude of the weapon so as to employ such information in ballistic computing programs adapted to provide the operator shouldering the weapon indications in real time relating to the shooting attitude to be given to the weapon with the purpose of hitting a target.
U.S. Pat. No. 7,296,358 B1, which is incorporated by reference, discloses an electronic vertical angle sensing and indicating device for use on aiming systems that are provided for bow sights and for other aiming sights for projectile launchers. Improved vertical level measurement and display minimizes the left-right drift of a projectile by sensing and indicating to the user when the projectile launcher is tilted slightly prior to release of the projectile.
Document VAGANAY J ET having title “mobile robot attitude estimation by fusion of inertial data” (Proceedings of the international conference on robotics an automation—ATLANTA, May 2-6 1993), which is incorporated by reference, discloses an attitude estimation system based on inertial measurements for a mobile robot wherein five low-cost inertial sensors are used.
US636826 B1, which is incorporated by reference, discloses an orientation angle detector using gyroscopes for detecting X-, Y- and Z-angular velocities which are time-integrated to produce pitch, roll and yaw angles (gamma, beta, alpha) of the orientation. Two accelerometers are used to obtain tentative pitch and roll angles in order to correct the pitch and roll angles, and two terrestrial magnetometers are used to obtain a tentative yaw angle so as to correct the yaw angle. When the tentative pitch, roll and yaw angles are defined accurate (50), the integrated pitch, roll and yaw angles are corrected (60) by the tentative pitch, roll and yaw angles.